Area Calculator
Quick Area of Any Shape
Pick a shape, enter its dimensions, and get the area instantly. This is a quick multi-shape utility — one simple formula per shape — not a deep, dedicated solver. For a full circle breakdown (radius, diameter, circumference, arc & sector) use the Circle Calculator; for a full general-triangle solve, use the Triangle Calculator.
Just need this? Great. Need the diameter, circumference, or arc/sector too? The Circle Calculator derives all of them from any one known value.
Understanding 2D Area
Area measures how much flat space a shape covers. This calculator is intentionally scoped as a quick, single-formula tool for seven common shapes — enter dimensions, get the area, done. It is not a deep per-shape solver: for that, use a dedicated tool like the Circle Calculator or Triangle Calculator, linked throughout this page.
Square, rectangle, triangle, circle, trapezoid, parallelogram, and ellipse — the shapes you'll encounter most often in everyday measuring, homework, and quick estimates.
Each shape uses exactly one formula and nothing more — for example, circle mode here is just π × r². If you need to derive values from different starting points or work with angles, use a dedicated deep-solve tool instead.
The Seven Formulas
Square
Rectangle
Triangle
Circle
Trapezoid
Parallelogram
Ellipse
Quick Tool, Deep Tools Available
This calculator trades depth for speed: no angles, no deriving from multiple starting points, just one dimension set in and one area out. If you're working specifically with circles — need the diameter, circumference, or arc length and sector area too — the Circle Calculator derives every circle value from whichever one you already know. If your shape is a general (possibly non-right) triangle and you only know some sides and angles, the Triangle Calculator solves the whole triangle using the Law of Cosines and Law of Sines.
Square, rectangle, triangle, circle, trapezoid, parallelogram, ellipse.
A single, simple formula — no angles or multi-directional solving.
Area is always expressed in square units, whatever unit you enter.
Key Takeaways
- This is a quick, multi-shape utility — one simple formula per shape, not a deep solver.
- Area is always in square units, whatever linear unit you enter your dimensions in.
- Need more depth on circles or triangles? The Circle Calculator and Triangle Calculator solve those shapes fully.
Frequently Asked Questions
- Choose a shape from the dropdown — square, rectangle, triangle, circle, trapezoid, parallelogram, or ellipse.
- Enter the required dimensions for that shape (all values must be positive numbers).
- Click "Calculate" to see the area.
No — by design, this is a quick area utility. Each shape uses exactly one simple formula (for example, circle mode is just π × r²) and nothing more. If you need a deeper solve for a specific shape — deriving every value from any known starting point, working with angles, arcs, or sectors — use a dedicated tool instead, like the Circle Calculator or Triangle Calculator.
Seven of the most common 2D shapes: square, rectangle, triangle, circle, trapezoid, parallelogram, and ellipse. Each one uses its own single-purpose formula, listed in full in the formula reference below.
This calculator is unit-agnostic — enter all dimensions for a shape in the same unit (all in centimeters, all in inches, and so on), and the resulting area will be in that unit squared (cm², in², etc.). Mixing units within a single calculation will give an incorrect result.
A trapezoid has exactly one pair of parallel sides, which are usually different lengths, plus the perpendicular height between them. All three values — both parallel sides and the height — are required because the trapezoid's area formula averages the two parallel sides before multiplying by the height.
A circle has a single radius in every direction, while an ellipse has two different radii — a semi-major axis (the longer one) and a semi-minor axis (the shorter one). A circle is really just a special case of an ellipse where both axes are equal, which is why the two formulas look so similar: π × r² for a circle versus π × a × b for an ellipse.